O2 is investigating the potential leak of mobile phone numbers to any website its customers visit on their devices.
Lewis Peckover, who describes himself as a web systems administrator, has created a website that displays the information sent to a website when it is visited from a mobile phone. This information helps the site work with the browser. However, when you access Peckover's test site using an mobile phone on an O2 contract, the user's phone number is displayed. A test by Mobile revealed its mobile number when the site was visited using a device on an O2 contract.
Peckover said he discovered the breach yesterday (24 January) lunchtime, while investigating ways to verify a user is on a mobile network. He said the leak appears to be O2 specific and also relates to MVNOs like Tesco Mobile and giffgaff.
A spokesperson for O2 said: 'We’re investigating the reports and will update as soon as we can.'